OBJECTIVES To study effects of various concentrations of hydrogen peroxide on mature waterline biofilms and in controlling planktonic (free-floating) organisms in simulated dental treatment water systems; and to study in vitro the effects of 2%, 3%, and 7% hydrogen peroxide on the removal of mature biofilms and inorganic compounds in dental waterlines. METHODS Four units of an automated denta...

saliva into the line due to lack of anti-retraction valves. Even a small amount of Pseudomonas aeruginosa in a municipal water system can contribute to the dental chair unit contamination problem because dental chair units provide a different environment with small bores, narrow lumens and periods of stagnant water. However, if the water is well maintained according to current hygiene guideline...

BACKGROUND The maximum recommended level of microbial contamination of water from dental unit waterlines (DUWL) is 200 colony-forming units per milliliter (CFU/mL). This article addresses the importance of water selection in achieving that standard. METHODS Microbial contamination in water samples from 75 new dental units, with a closed-circuit water system, were compared using combinations o...

Dental unit waterlines are heavily colonized by bacteria which contaminate the water used to perform intraoral, and sometimes invasive, procedures. There is little information on the nature of the biofilm colonizing the flexible plastic tubing used to supply water to the different handpieces. We have therefore undertaken quantitative microbial analysis and ultrastructural studies of these biofi...